Abstract: The study aims to
determine the effect of formulated PEFB trichokompos and P fertilizers on growth, physiology, production and P
uptake of onion in peatlands. This research used experimental factorial
randomized completely block design and three replications. Trichokompos PEFB
formulated as the first factor is composed of four levels (0, 5, 10 and 15 ton
ha-1) and P fertilizers as the second factor consists of four levels (0, 120,
180 and 240 kg ha-1 P₂O5). Parameters measured were chlorophyll content, photosynthesis
rate, stomataH2Oconductivity , the concentration of CO2 in the cell,
transpiration rate, plant height, number of tillers, number of tubers per hill,
the diameter of the bulbs, fresh weight of tuber per hill, plant dry weight and
P uptake. The results showed trichokompos PEFB formulated 15 ton ha-1 can
increase the response of onion production as tuber diameter and fresh weight
per hill and P uptake response respectively by 25.58%, 74.92% and 76.39%. While
the physiological responses seen to decrease thestomatal H2O conductivity and
transpiration rate of respectively 21.43% and 28.79% compared with no PEFB
formulatedtrichokompos. Provision of fertilizer P 120 P2O5 ha-1 can improve
physiological responses such as H2O on stomatal conductivity, increased growth
responses such as plant height, such as the production response tuber diameter
and fresh weight per hill and P uptake response respectively by 7.69%, 22.25%,
26.23%, 56.21% and 44.26% compared with no fertilizer P. combination
trichokompos PEFB formulated 15 ton ha-1 with manure P 120 P2O5 ha-1 is the
best treatment combination, with the highest production response namely 7.65 g
(1.91 ton ha-1) fresh weight per hill and increased 214.81% compared with no
treatment trichokompos PEFB formulated and fertilizer P.